Cable for conducting simultaneously electricity and light

ABSTRACT

A cable (K) comprises at least one lead (A) and at least one insulating layer (I). In communication technology, communications are transmitted between two apparatuses by cables of various types. In order to reduce to a minimum the number of cables and cable connections necessary, cables with a high transmission capacity are preferred. In order to substantially increase the transmission capacity of a cable (K) with at least one lead (A) and at least one insulating layer (I), the insulating layer (I) is made for optical transmission purposes of an optically conductive material. Optical transmission channels can be obtained using optically conductive materials for the insulating layers of all cables with one or more insulating layers, for example flat cables, coaxial cables, mains cables, etc., without having to increase the cross-section of the cable or to provide separate connections for additional cables in the appliances to be connected.

BACKGROUND OF THE INVENTION

The invention concerns a cable with at least one core and at least onelayer of insulation

Electric cable is employed is almost every field of technology. Antennasignals for example are forwarded to receivers, television or radioreceivers for example, by way of coaxial cable. Telephone communicationsare no longer conceivable without coaxial cable. In this area inparticular, however, coaxial cable is being increasingly replaced withoptical cable, which features an essentially more extensive band widthand lower attenuation, because light is a form of energy that requiresno shielding, and because the crosstalk that is so irritating withcoaxial cable does not occur at all with optical.

Many types of equipment, television sets and video recorders forexample, are designed only for coaxial cable. The video signal istransmitted from the recorder to the television set over a coaxialcable. To operate a combination television set and video recorder,however, it is of advantage to transmit control signals in addition tovideo and audio signals between the two units. Due to the narrow bandwidth and especially due to the distortions occasioned in the videosignal and the extreme difficulty of separating the video signal fromthe audio signal inside the equipment it is not advisable to transmitcontrol signals over the coaxial cable along with the video signals. Oneof skill in the art is accordingly compelled to provide a separate lineto transmit the control signals, which is undesirably expensive. Theseparate components in other types of consumer electronics--high-fidelity sets with record players, compact-disk players, radioreceivers, audio-cassette recorders, and amplifiers for example-- areconnected by simple cable. When control signals must be transmittedalong with music and speech, a separate line is also necessary for theaforesaid reasons.

SUMMARY OF THE INVENTION

The object of the present invention is accordingly to provide a means oftransmitting information between two pieces of equipment connected by acable without a separate line and without detriment to the transmissionover the cable of either the information or the energy.

This object is attained in accordance with the invention, a cable withat least one core and at least one layer of insulation, in that thelayer of insulation is made of optically conductive material andtransmits the information optically.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the drawings,wherein

FIG. 1 is a transverse section through a singlecore cable in accordancewith the invention,

FIG. 2 is a longitudinal section through a cable in accordance with theinvention with a connector at one end,

FIG. 3 is a longitudinal section through a cable in accordance with theinvention with a connector at one end, and

FIG. 4 illustrates an information-transmission system comprising a videorecorder, a television set, and a cable in accordance with theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a transverse section through a single-core cable K inaccordance with the invention. Its core A is made of wire and extendsthrough a cylindrical, optically conductive layer I of insulation.

FIG. 2 is a longitudinal section through the cable K illustrated intransverse section in FIG. 1. One end is secured in a connector in theform of a plug VS. The outside of plug VS terminates in a tubular sleeveH that extends partly over cable K Extending along the axis of sleeve His a pin S that is electrically connected to the core A of cable K.Between pin S and sleeve H is a tubular coupling L with a cross-sectionthat preferably matches the cross-section of the layer I of insulationaround cable K. Layer I of insulation can rest against optical couplingL but need not do so, because any space between the two components,although it might attenuate the optical connection, could not interruptit.

The light, indicated by the arrows, travels from layer I of insulationinto optical coupling L, emerges from its face, and enters for examplethe optical coupling of a jack VB that plug VS fits into and that canfor example be accommodated in the housing of a piece of equipment.

The outside of the jack VB in FIG. 3 terminates in a sleeve H thatextends partly over cable K. Extending along the axis of sleeve H is acylindrical opening R that accommodates the pin S on plug VS and iselectrically connected to cable K. Embedded between the cylindricalopening R that accommodates the pin S in plug VS is an also cylindricaloptical coupling L. Its cross-section preferably matches that of thelayer I of insulation on cable K. As with the plug VS illustrated inFIG. 2, the layer I of insulation on cable K can rest against opticalcoupling L but need not do so, because any space between the twocomponents could not interrupt the optical connection. The light,indicated by the arrows, leaves the optical coupling L of the plug VSillustrated in FIG. 2 and enters the optical coupling L in jack VB, fromthe end of which it shines into the layer I of insulation on cable K.

Cable K can be secured in plug VS or jack VB by known, threaded,tension, or soldered connections. The pin S on plug VS is secured in thecylindrical opening R in jack VB by springs or by fitting tight,establish an electric contact between pin S and cylindrical opening R.

When, as illustrated in FIG. 2 for example, the light travels from thetransparent layer I of insulation on cable K into optical coupling L, itis of advantage for the cross-section of coupling L to be larger thanthat of layer I of insulation to ensure that all the light leaving theinsulation will be intercepted by the coupling.

If on the other hand the light travels from optical coupling L into theoptically conductive layer I of insulation on cable K, it is ofadvantage for the cross-section of optical coupling L to be smaller thanthat of layer I to ensure that all the light leaving the coupling willbe intercepted by the insulation.

If light is to be transmitted alternately in each direction, however, itwill be more effective for the cross-section of optical coupling L tomatch that of layer I of insulation.

The information-transmission system illustrated in FIG. 4 represents oneway of employing the cable in accordance with the invention.

A video recorder V is connected to a television set F by a coaxial cableK with a layer of insulation in the form of a dielectric that conductslight effectively in accordance with the invention. The ends of cable Kare secured in plugs VS for example as illustrated in FIG. 2. Mounted onthe components--video recorder V and television set F--are jacks VB thatmatch plugs VS, which are also provided with an optical coupling facingthe optical coupling L on plug VS. Connected to the end of the couplingin each plug VS opposite plug VS is an optical transmitter and/orreceiver. The light from the optical transmitter in whatever componentis transmitting travels through the optical coupling in the jack to theoptical coupling on the plug, through coaxial cable KA, and through theoptical coupling on the plug and the optical coupling in the jack on thereceiving component. Both video recorder V and television set F can beprovided with an optical transmitter, an infrared-emitting diode forexample, and an optical receiver to allow the transmission ofinformation in both directions.

Since the video signals are transmitted electrically and the controlsignals optically, they have no effect on each other and need not beseparated in video recorder V or television set F. Finally, there is noneed for two different cables to transmit information, each with a plugat each end and a jack on each component. A single cable is enough.

Another advantage is that optical transmission over the coaxial cable isnot interfered with by infrared remote controls.

The cable in accordance with the invention, a combination of electricand optical cable, is not limited to the application described herein.The cable in accordance with the invention can be employed tosimultaneously transmit information of any type both electrically andoptically between any two components--repeaters, terminals, data banks,etc. for example.

In a ribbon-type cable for example, the individual wires can beinsulated with an optically conductive material to provide as manyoptical-transmission channels as there are wires. Optically conductiveinsulation can also be employed in power cords and other cables thattransmit energy to provide optical channels without increasing thecross-section of the cable. A power or energy cable will accordinglytransmit not only electricity but also information of all types withoutone mode prejudicing the other.

The layer I of insulation around the cable can for example be dividedinto several mutually optically insulated transmission channels bylongitudinal optically insulating intermediate layers to create severalinformation channels without increasing the cross-section of the cablebut considerably augmenting its transmission capacity.

If the cable in accordance with the invention is compared with aconventional cable of the same specifications and cross-section, thetransmission capacity of the cable in accordance with the invention willbe found to considerably exceed that of the known embodiment.

We claim:
 1. A cable for conducting simultaneously electricity andlight, comprising: at least one electrically conducting core; and atleast one layer of insulation surrounding said core; said layer ofinsulation being comprised of optically conductive material forconducting light therethrough, so that electrical signals can beconducted through said core simultaneously with light signals throughsaid insulation layer; a connector secured to at least one end of saidcable and resting against said optically conductive insulation layer forproducing an optical coupling; said connector having a portion restingagainst said insulation layer, said portion being transparent andcomprised of optically conductive material or producing an opticaltransmission channel; said insulation layer being a cylindrically-shapedglass filament having an inside surface, said core being fused to saidinside surface; said insulation layer comprising at least twosub-layers; at least one optically insulating intermediate layer betweensaid two sub-layers, said sub-layers being optically conductive.
 2. Acable for conducting simultaneously electricity and light, comprising:at least one electrically conducting core for conducting electricalsignals in absence of an electrical field; and at least one layer ofinsulation surrounding said core; said layer of insulation beingcomprised of optically conductive material for conducting lighttherethrough, so that electrical signals can be conducted through saidcore simultaneously with light signals through said insulation layer,said conducting core and said insulation layer being free of anelectrical field.
 3. A cable as defined in claim 2, including aconnector secured to at least one end of said cable and resting againstsaid layer of insulation comprised of optically conductive material,said connector being transparent where said connector rests against saidoptically conductive layer of insulation to produce an optical coupling.4. A cable as defined in claim 3, wherein said connector has a portionresting against said optically conductive insulation layer, said portionof said connector being comprised of optically conductive material forproducing an optical transmission channel.
 5. A cable as defined inclaim 2, including an electrically conductive layer surrounding saidlayer of insulation and being an outer electrical conductor spaced fromsaid core by said insulation layer, so that said cable is a coaxialcable; said insulation layer dielectric and being optically conductive.6. A cable as defined in claim 5, wherein said insulation layercomprises a cylindrically-shaped glass filament with an inside surface,said core comprising an inner conductor fused to said inside surface ofsaid cylindrically-shaped glass filament.
 7. A cable as defined in claim2, wherein said insulation layer comprises at least two sub-layers toform two optically-insulated transmission channels; and at least oneoptically insulating intermediate layer located between said twosublayers, said sublayers being comprised of optically conductivematerial.
 8. A cable as defined in claim 2, wherein said cable has aribbon-shape, a plurality of insulating layers surrounding a pluralityof electrically conducting cores and being optically conductive, saidoptically conductive insulation layers being optically insulated fromeach other.